 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
COP8782CN Datasheet(PDF) 6 Page - National Semiconductor (TI) |
|
|
||||||||||||||||||||||||||||||
COP8782CN Datasheet(HTML) 6 Page - National Semiconductor (TI) |
|
|
6 / 28 page  Functional Description (Continued) ers The device can be configured to have either 64 or 128 bytes of RAM depending on the value of the ‘‘RAM SIZE’’ bit in the ECON (EPROM CONFIGURATION) register The sixteen bytes of RAM located at data memory address 0F0 – 0FF are designated as ‘‘registers’’ These sixteen registers can be decremented and tested with the DRSZ (Decrement Register and Skip if Zero) instruction The three pointers X B and SP are memory mapped into this register address space at addresses 0FC 0FE and 0FD respectively The remaining registers are available for general usage Any bit of data memory can be directly set reset or tested All of the IO registers and control registers (except A and PC) are memory mapped Consequently any of the IO bits or control register bits can be directly and individually set reset or tested Note RAM contents are undefined upon power-up ECON (EPROM CONFIGURATION) REGISTER The ECON register is used to configure the user selectable clock security and RAM size options The register can be programmed and read only in EPROM programming mode Therefore the register should be programmed at the same time as the program memory locations 0000 through 0FFF Hex UV erasable parts are shipped with 0FF Hex in this register while the OTP parts are shipped with 07F Hex in this register Erasing the EPROM program memory also erases the ECON register The device has a security feature which when enabled pre- vents reading of the EPROM program memory The security bit in the ECON register determines whether security is en- abled or disabled If the security option is enabled then any attempt to externally read the contents of the EPROM will result in the value E0 Hex being read from all program mem- ory locations If the security option is disabled the contents of the internal EPROM may be read The ECON register is readable regardless of the state of the security bit The format of the ECON register is as follows TABLE I Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 X X SECURITY CKI 2 CKI 1 X RAM SIZE X Bit 7 e X Don’t care Bit 6 e X Don’t care Bit 5 e 1 Security disabled EPROM read and write are allowed e 0 Security enabled EPROM read and write are not allowed Bits 43 e 11 External CKI option selected e 01 Not allowed e 10 RC oscillator option selected e 00 Crystal oscillator option selected Bit 2 e X Don’t care Bit 1 e 1 Selects 128 byte RAM option This emulates COP840 and COP880 e 0 Selects 64 byte RAM option This emulates COP820 Bit 0 e X Don’t care RESET The RESET input when pulled low initializes the microcon- troller Initialization will occur whenever the RESET input is pulled low Upon initialization the Ports L G and C are placed in the TRI-STATE mode and the Port D is set high The PC PSW and CNTRL registers are cleared The data and configuration registers for Ports L G and C are cleared The external RC network shown in Figure 4 should be used to ensure that the RESET pin is held low until the power supply to the chip stabilizes TLDD11299 – 7 RC t 5X Power Supply Rise Time FIGURE 4 Recommended Reset Circuit OSCILLATOR CIRCUITS Figure 5 shows the three clock oscillator configurations available for the device The CKI 1 and CKI 2 bits in the ECON register are used to select the clock option See the ECON REGISTER section for more details TLDD11299 – 8 FIGURE 5 Crystal External and R-C Connection Diagrams A Crystal Oscillator The device can be driven by a crystal clock The crystal network is connected between the pins CKI and CKO Table II shows the component values required for various standard crystal frequencies B External Oscillator CKI can be driven by an external clock signal provided it meets the specified duty cycle rise and fall times and input levels In External oscillator mode G7 is available as a gen- eral purpose input andor HALT restart control http www nationalcom 6 |
Similar Part No. - COP8782CN |
|
Similar Description - COP8782CN |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
